1. The problem statement, all variables and given/known data The bullet strikes a block of wood which exerts, on average, a force of 50,000N opposing the motion of the bullet. How far does the bullet penetrate? Mass of bullet = 25g Initial velocity of bullet = 350 m/s Final velocity of bullet = 0 m/s 2. Relevant equations Ei+work=Ef K = ½mv^2 Energy = Force * Displacement 3. The attempt at a solution Please excuse my attempt of it's egregiously wrong, I was just introduced to energy yesterday; this is one of the first problems I'm doing. Anyways, because the final velocity of the bullet is zero, the bullet must have lost all of its energy, making Ef=0 J. The bullet initially had kinetic energy, making Ei=K. Thus, my new equation is K+work = 0 J ½mv^2+work=0 J I also know that the problem gave me how many Newtons oppose the object, but I need to find out how much energy it used. Since Energy = Force*Displacement, I can rewrite the equation as: ½mv^2+(F*Δx) = 0 J So I solved it below... ½(.025kg)(350 m/s)^2+(-50000N*Δx) = 0 J Δx=.03m Did I do this problem right? If not, what did I do wrong?